New York City Mayor Michael Bloomberg speaks while a map of the projected 2050s 100-year flood plain of New York City is displayed in New York, Tuesday, June 11, 2013. Removable flood walls would be set up for much of lower Manhattan, a 15-to-20-foot levee would guard part of Staten Island and gates and levees would shield Brooklyn as part of a nearly $20 billion plan Mayor Michael Bloomberg proposed Tuesday to protect New York City from storms and the effects of global warming. (AP Photo/Seth Wenig)

New York City Mayor Michael Bloomberg speaks while a map of the projected 2050s 100-year flood plain of New York City is displayed in New York, Tuesday, June 11, 2013. Removable flood walls would be set up for much of lower Manhattan, a 15-to-20-foot levee would guard part of Staten Island and gates and levees would shield Brooklyn as part of a nearly $20 billion plan Mayor Michael Bloomberg proposed Tuesday to protect New York City from storms and the effects of global warming. (AP Photo/Seth Wenig)